Plunger diaphragm pump



, Feb. 21, 1967 w. H. GROWALL ET AL 3,304,870

PLUNGER DIAPHRAGM PUMP Filed Feb. 15, 1965 5 Sheets-Sheet 1 FIG. 1

/Nl/EN7'O/?$ WILLIAM H. GROWALL JAM S WISEMAN A TORNEVS Feb. 21, 1967 w. H. GROWALL ET AL 3,304,870

PLUNGER DIAPHRAGM PUMP INVENTORS WILLIAM H. GROWALL JAMES WISEMAN TTORNEIS Feb. 21, 1967 w. H. GROWALL ET AL 3,304,870

PLUNGER DIAPHRAGM PUMP Filed Feb. 15, 1965 5 Sheets-Sheet 5 FIG. 3

INVENTORS WILLIAM H. GROWALL JAMES WISEMA I4 I p P l T TORNEVS Feb. 21, 1967 w. H. GROWALL ET AL 3, 0

I PLUNGER DIAPHRAGM PUMP Filed Feb. 15, 1965 5 Sheets-Sheet 4 -Feb. 21 1967 I w, w' ET AL 3,304,870

PLUNGER DIAPHRAGM PUMP s sheets-sheet 5 Filed Feb. 15, 1965 INVENTORS GROWALL JAMES WIS E MA WlLLlAM ATTORNEYS United States Patent Ofiice 3,304,870 PLUNGER DIAPHRAGM PUMP William H. Growall and James Wiseman, Detroit, Mich., assignors to Growall Manufacturing Company, Detroit, Mich, a corporation of Michigan I Filed Feb. 15, 1965, Ser. No. 432,526

20 Claims. (Cl. 103-44) The present invention relates toan improved combination of plunger pump and diaphragm pump units which may be constructed with little or no increase in size, weight or cost as compared with either a conventional plunger or diaphragm pump of similar capacity. Yet the improved pump avoids many known drawbacks of the latter and has many advantages of its own over either type, or known combinations thereof.

Thus, a customarily constructed piston or plunger pump has limiting endurance characteristics which make itunsuitable for many applications, such as handling of abrasive fluids or materials with an adhesive content. Also in installations handling extremely high pressure it be comes a very difiicult matter to provide .an adequate lubricant for the cylinder walls and piston rings, due to the fact that many of the liquids pumped. contain abrasive materials and no lubricant qualitiesv whatsoever. In many cases an oil bath system of lubrication is not practical, as when an edible material is being pumped, because of leaking by piston rings of contaminating oil; in addition to the fact that in some installations a liquid being pumped, and which may leak at elevated pressure past the piston, may be highly detrimental to the latters guiding mechanism, Wrist pins, connecting rod bearings, main bearings, etc.

In reference to the conventional diaphragm pump, it usually has a driver connecting rod attached to the center of a diaphragm, and power is transmitted to this point only. Therefore, the area surrounding the center is dependent upon its own tensile strength to avoid damage or destruction when a load is placed against it, either on an intake or discharge stroke. Since the strength of the diaphragm is limited, especially after extended use, its pressure handling capability must remain low. 7

In general, it is an object of the invention to provide an improved plunger-diaphragm pump which avoids the above-mentioned drawbacks of known plunger or diaphragm pumps, as well as combined plunger and diaphragm pumps of which we are aware, and which is there fore capable of pumping efficiently, and in large or small volume. a vast number of different materials ranging from water through paints and other surface coating materials, molding materials, disinfecting and cleaning liquids, adhesives, and the like. Water is hereinafter mentioned simply as being typical.

In accordance with the invention, and as distinguished from known piston pumps, the improved pump has all of its moving parts submerged in oil, which-in turn is sealed safely and securely from any liquid material being pumped. Such component parts, save those in direct contact with the liquid being pumped, may be constructed from the low cost materials, since there is no problem of rust or corrosive action upon bearings,-driving mechanisms, etc. Moving parts, as well as associated stationary components, are assured of long life by an efficient lubrication system.

Moreover certain plunger sealing members of the improved pump are located between two substantial bodies all) 33%,370 Patented Feb. 21, 1967 of clean oil. Hence, not only are practically all moving parts lubricated in a bath of oil, but no-air is present to seep by the plunger members and, accordingly, cause air pocket accumulation, such as would prevent the build up of extremely high pressures which the improved pump is designated to produce.

In comparison with existing diaphragmpumps, the improved combination pump applies a plunger-pressurized body of oil over each square inch of its diaphragm surface, thus transmitting such pressure against an equally distributed load on the other side of the diaphragm surface. Due to this principle, the force and load are equalized at all required pumping conditions, and the diaphragm is not subjected to damaging or destructive stress, hence may exert pumping forces incapable of attainment in a rod-operated diaphragm pump.

Further in accordance with the general concept of the invention, the improved pump is constructed of component, fixed casing and housingparts which are assembled to one another in a manner to enable the same to be readily and quickly dismantled for inspection or servicing, and equally readily reassembled, these housing and casing components also having improved means for draining liquid therefrom.

More particularly, it is an object of the invention to provide a pump having a plunger actuating cam unit immersed in oil in a combined cam and transmission casing, along with a speed-reducing and torque-increasing transmission unit connecting the cam unit to an external power source.

Moreover, the invention also provides an improved type of plunger unit driven in reciprocation by the power unit including a pair of opposite plunger heads rigidly coupled together for vacuum and pressure strokes in a pair of oil cylinders on opposite sides of the cam-transmission casing. Thus, the undesirable effects of side thrust, as in a connecting rod-operated plunger, are avoided, the cam unit transmitting a strictly linear line of reciprocating action to the plunger unit and its heads.

Still more specifically, the invention provides an improved type of dual roller cam follower for coaction with the cam unit, including apair of rollers having means cradling the same on a pivotal axis on each of the plunger heads, these rollers smoothly and continuously following the cam contour as the latter is driven at reduced speed by the transmission in a way to eliminate noise.

In another specific aspect, the pump of the invention has valved balancing provisions built into each of its oil pressurizing plungers to permit a compensating flow of oil from one side of the latter to the other, when the plunger and cylinder in question are in a vacuum cycle.

For a different, though related purpose, the pump of the invention preferably incorporates an oil pressure equalizing or balancing unit in the event of an objectionably high build up vof oil pressure on either side of the system, bypassing abnormal high pressure to the lower pressure side.

The foregoing as well as other objects will become more apparent as this description proceeds, especially when considered in connection with the accompanying drawings illustrating the invention, wherein:

FIG. 1 is a top plan of the improved dual acting plunger-diaphragm pump, being in part broken away and in horizontal section in a plane through the cylinder axis of the pump, as well as in further section parallel to that plane and closer toward the viewer;

FIG. 2 is a side elevational view, as from the bottom of FIGfl, being partially broken away and sectioned vertically along a line approximating the broken line 2-2 of FIG. 1;

FIG. 2A is a plan view, as from the line 2A-2A of FIG. 2, showing a valve mounting plate of a pumped liquid distributing valve unit of the pump;

FIG. 3 is a view partially broken away and in vertical section along line 33 of FIG. 1 through the cam and transmission casing of the pump, this view being further sectioned on other vertical and parallel planes proceeding in the direction away from the viewer;

FIG. 4 is, in the main, a top plan view, being broken away and horizontally sectioned along line 44 of FIG. 2;

FIG. 5 is a view partially broken away and in horizontal section on line 5-5 of FIGS. 2 and 3; and

FIG. 6 is a side elevational view, partially broken away and in vertical section, corresponding for example to the right-hand side of FIG. 3, showing an improved oil pressure equalizing or balancing device of the pump.

The improved dual-type plunger and diaphragm pump of the invention is generally designated by the reference numeral 10, and it is symmetric as to its operating and control inst-rumentalities about a central vertical plane, designated A-A in FIGS. 1 through 5 of the drawings. Accordingly, the following description of such components, as expressed in regard to one-half of the structure, for example, its right or left hand side, also applies to the identical other half.

Pump 10, in general reference to its basic components, comprises an oil-filled main casing, generally designated 12, containing certain power transmission and drive cam provisions to be described, and the casing has fitted to opposite ends thereof a pair of pump cylinder and manifold housings 14, which housings communicate with diaphragm pump units 16, all as illustrated in FIGS. 1 through 5 of the drawings.

The diaphragm units 16 are in turn connected to a central flow distributor valve chest 18, as best shown in FIGS. 1 and 2; and the chest 18 has intake and discharge fittings 20, 22, respectively, adapted to be connected-to a source of liquid to be pumped and to a disposal point. Valve chest 18 is also connected with an oil pressure balancing or equalizing unit 24 (FIG. 6) for a protective purpose to be described; and certain plunger components (also to be described) within the housings 14 are designed for a related function.

The power transmission and drive cam casing 12 is in the form of a rugged body casting providing an upright base or body 26 adapted to rest upon a suitable horizontal support. The casing 12 has an arcuate top portion 27 to accommodate certain sprocket means therein, and is also formed to provide opposed laterally opening bosses 28. Each cylinder and manifold housing 14 has an annular radial flange 29 presenting a projecting rim formation 30 which pilots accurately in a casing boss 28, with a sealing gasket 31 interposed. Each housing 14 also has an elongated, hollow cylinder portion 31' fitted with an elongated steel liner 32, and cylinder portion 31 is equipped within the flange 29 with an O-ring 32 surrounding and externally sealing the liner, which defines an oil cylinder space 33 of each of the cylinder and manifold housings 14.

The opposed cylinder and manifold housings 14 are accurately mounted by their integral rims 30 in the aper tured bosses 28 of the main casing 12, with the cylinders 33 thereof in accurate axial alignment with one another, and with the space between the housing bore and liner 32 well sealed by the O-ring 32, as shown in FIG. 4.

The casing 12 has at the rear thereof a large size opening 34, into which is piloted a rim of a recessed rear closure plate 35, and an outwardly projecting marginal flange 36 of this plate is bolted to the rear of casing body 26 about opening 34. Thus certain bearing provisions of the cover or closing plate are properly centered in relation to the casing body or base 26. Closure member 35 is provided with an outwardly projecting and opening tubular boss 38 (FIGS. 1 and 4), and directly beneath the boss 38 the plate 35 is provided, as shown in FIG. 5, with a second outwardly projecting boss 39 which is a closed or blind one, as distinguished from the axially outwar-dly exposed boss 38.

Furthermore, the forward upright wall of casing base 26 is provided, opposite the boss 38 of rear closure plate 35, with an opening 40 in the wall in question, this opening being covered by a closure plate 41, which is secured to that wall, with a gasket interposed, by a series of bolts 42. The closure 41 has an inwardly projecting tubular boss 43. Directly beneath the opening 40 and plate 41 the forward wall of base 26 of casing 12 is provided (FIG. 5) with an internally recessed, externally closed boss 44; and the lower casing and plate bosses 44, 39, respectively, are in true axial alignment with one another, as are also the respective bosses 43, 48 thereabove.

As shown in FIG. 4, the main drive shaft for the pump 10 is designated by the reference numeral 46. It extends outwardly through the boss 38 of casing closure plate 35, where it carries a double pulley 47, which is a power-input member for the pump 10 driven by an appropriate motor, engine or other prime mover unit. Inwardly of this zone the main shaft 46 has an anti-friction journal in boss 38 by means of a rugged double ball bearing 49, the shaft being oil-tight sealed by an appropriate packing 50. The opposite end of shaft 46 is similarly journaled in the boss 42 of closure plate 41 by means of a heavy duty, slip fit roller bearing 52, the inner race of which is press fitted onto a reduced diameter end of the shaft.

Referring to FIG. 5, a secondary idler or countershaft of the pump 10, which parallels shaft 46, is generally designated 54, being located beneath and in a vertical plane including the axis of shaft 46. countershaft 54 is journaled at one end in a roller bearing 55 in the lower boss 44 of the body 26 of casing 12; and the opposite end of shaft 54 is similarly journaled by a double ball bearing 56 in the opposite boss 39 of closure plate 35. Thus, the shafts 46, 54 are supported for rotation in casing 12 by means of efficient heavy duty bearing provisions; and it is evident that upon removal of pulley 47 from shaft 46 and closure plate 35 from main casing body 26, the entire bearing structure, also various drive provisions to be described, is accessible for inspection and servicing. Initial assembly is also facilitated.

Directly within the recessed closure plate 35, main drive shaft 46 (as shown in FIG. 4) has fixedly secured thereon, as by a key 58, a relatively small diameter chain sprocket 59, about which a primary power input chain 60 (FIG. 3) is trained downwardly around a larger diameter sprocket 61 fast on countershaft 54 directly therebeneath, as by a key 62 on the hub of the sprocket (FIG. 5). A pair of secondary driving sprockets 64, 65 of like diameter, considerably smaller than that of the driven sprocket 61, are also secured by key means 66 to countershaft 54, either as individual sprocket elements or as a unitary, double sprocket structure. A pair of secondary driving chains 68 are trained upwardly, as shown in FIG. 3, about the respective small diameter sprockets 64, 65, and around a pair of secondary driven sprocket rings 69, 70, respectively, which are of larger diameter than and disposed directly above the sprockets 64, 65.

Sprocket rings 69, 70 are mounted by a tubular sprocket hub 71, which is rotatably journaled on main drive shaft 46 through the agency of sets of heavy duty, free floating roller bearings 72, and hub 71 is provided with an integral radially extending circular flange 73. Sprocket rings 69, 70 are telescoped over stepped cylindrical formations of hub 71; and an annular series of screws or bolts 75, with interposed rigidifying spacers, serve to secure the sprocket members 69, 70 to the flange 73, in fixed coaxial relation to one another on the sprocket hub 71, as shown in FIG. 4.

Thus, a chain of power transmission is established, as illustrated in FIGS. 3, 4 and 5, from a prime mover (not shown) through pulley 47, main drive shaft 46, primary sprocket 59, chain 60, large diameter sprocket 61, countershaft 54, small diameter sprockets 64, 65, chains 68, and large diameter sprockets 69, 70 on main shaft 46, whereby the sprocket hub 71, as anti-friction journaled on shaft 46, is driven at quite a great speed reduction and power torque increase ratio.

This drive is employed to rot-atively power a cam unit, generally designated 74, and through the latter, to cause horizontal reciprocating action of a plunger unit, generally designated by the reference numeral 76, which includes oppositely disposed, rigidly interconnected hollow plunger heads 77, in a manner to be described.

Referring to FIG. 3, the cam unit 74 comprises a single lobe-type cylindrical cam body 78 which is pivoted at 79 on the main shaft 46 with sufiicient eccentricity to produce a desired horizontal reciprocatory throw of the plunger unit 76 in opposite directions. Cam body 78 is fixedly secured by a pin 81 and bolt 82 to the adjacent side of the sprocket hub 71 to rotate with the latter at the speed dropping and torque increasing ratio described above. Cam body 78 has a wear-resistant cylindrical steel sleeve 83 force fitted or shrunk thereon.

In accordance with the invention, an improved type of cradled, dual roller-type follower means is provided for coacti-on with the cam unit 74, acting to drive both of the heads 77 of the plunger unit 76 with substantial advantages over prior crank and connecting rod types of plunger drive.

Referring to FIGS. 3 and 4, each head 77 pivotally mounts a follower roll carrier or cradle 85, which is in the general form of a 90 yoke presenting pairs of arms 86, S7 diverging from a central apex pivot, and at this pivot location the cradle has a pair of needle bearings 88 journ-aling it on a transverse pivot pin, in the form of a stud 89 extending through opposed walls of the tubular plunger head 77, as best shown in FIG. 4. The respective pairs of yoke arms 86, 87 each receive a transverse journal pin 90, upon which an anti-friction follower roller 91 is journaled by a needle bearing 92.

The arrangement of the cradles 85 is such that, as illustrated in FIG. 3, the follower rolls 91 ride the periphery of the lobe of cam sleeve 83 continuously, their respective cradles 85 swinging about the pivot pins 89; and the result is to drive the plunger unit 76 and its attached plunger heads 77 in a smooth fashion, with an absolute minimum of side or transverse thrust upon the heads.

Referring to FIG. 4, the arrangement of the cradled pair of cam follower rolls 91 on each plunger head 77 is offset in a manner to bring the line of force from cam unit 74- directly axially of the head; and this use of two pairs of rolls 91, one at each side of the cam unit 74, results in the elimination of connecting rods, their wrist pins and eccentric straps, plunger guides, and the like, as well as occasioning a minimum side thrust on the plunger head 77, as indicated above, and its packing or sealing ring provisions, to be described. Since the pump 10 utilizes two opposed and spaced cylinders 33, instead of a double-acting plunger and cylinder arrangement, no outer piston or plunger rod packings are required. The packing provisions of the improved pump exert of themselves the entire function of guiding the plunger heads within cylinders 33, and without possibility of building up air pockets, as previously mentioned.

As illustrated in FIG. 3, the plunger unit 76, in the zone between the roll cradles 85, includes an elongated coupling yoke 93 integral at its opposite ends with the heads 77. Yoke 93 is provided with an elongated horizontal slot 93-, through which the main shaft 46 extends, thus accommodating the latter with a slight side clearance, adequate to prevent contact with the'plunger unit 76 as the latter follows its horizontal reciprocating path.

As 'best shown in FIGS. 3 and 4, each plunger head 77 is provided within its cylinder 33 with an integral, reduced diameter shoulder extension 94, upon which an annular cupped sealing ring of V-sh-aped cross section is disposed for sealing coaction with the surface of cylinder liner 32; and at a further reduced diameter zone, a sealing ring 96 is received, with an O-ring 97 in a groove of the ring to coact also with the liner. A second, outer sealing cup 98 is held in place directly outwardly of ring 96 by a washer 99; and an apertured cup-like cap 100 in turn locks the entire assembly of such sealing members rigidly on the outer end of plunger head extension 94. i

The head 77 and extension 94 are provided with an axially extending central bore 102 with which an inner axial valve port 103 of head 77 communicates; and cap 100 is provided with an aligned center port 104 opening to the cylinder space 33 of the cylinder and manifold housing 14. A valve check ball 107 is urged against the valve port or seat 103 by means of a coil compression spring 108 acting against the end cap 100, for a purpose to be described after the nature of the remaining basic components of oil and water sub-systems of pump 10 has been made clear.

As shown in FIGS. 1 and 4 of the drawings, each housing 14 is cast or otherwise formed to provide an integral, laterally extending oil duct or manifold 110, which communicates with the cylinder space 33 of the housing at an end opening 111 of said space; and the manifold in turn opens through a side port 112 to the diaphragm unit 16. Housing 14 also has an oil flow passage 114 through which it is adapted to be communicated with the oil pressure safety balancing or equalizing structure 24 shown in FIG. 6, as will be described.

As best shown in FIG. 1, the diaphragm unit 16 includes an upper dished housing head 115 and a lower dished housing head 116, these heads defining a space which is separated by a flexible corrugated diaphragm 117. The diaphragm is marginally clamped between annular flanges 118 of the housing members, through the agency of a pair of generally semi-circular clamp ring members 120. As shown in FIG. 2, the diaphragm 117 is additionally held in place against the flange 118 of the upper head 115 by a ring 120 and screws 120" so as to prevent significant oil leakage if the opposite housing head 116 is removed for cleaning.

Clamp ring members 120 have outwardly projecting ears 121 (FIG. 2) which are apertured to receive clamp bolts or studs 122 taken up by wing nuts 12.3; and the interior surface of each of the rings 120 is grooved or cupped in frustoconical cross section, as indicated in FIG. 1, thus to provide a wedging action as the studs 122 are taken up to draw the housing flanges 118 tightly toward one another and against the interposed margin of diaphragm 117.

Thus, the diaphragm constitutes a pumping element sealing off the oil side of the pumping system from the side actually pumping the water on the lower side of diaphragm 117, oil filling the chamber 124 above the diaphragm. A diaphragm chamber 125 beneath diaphragm 117 communicates through a water conduit member 127 with the distributing valve unit 18, which will be hereinafter described in detail.

It is believed that the operation of the pump 10, as described to this point, will be clear. With the unitarily connected plunger heads 77 reciprocated by cam unit 74, a stroke of each toward the latter of a predetermined length occasions a vacuum in the cylinder 33 on the opposite or outer-side of the head in question, causing the corresponding diaphragm 117 to rise under a corresponding vacuum in its upper oil cylinder 124, and in turn draw water to be pumped into the lower diaghragm chamber 125. As the plunger unit 76 changes travel direction, the Water is discharged through conduit 127 under oil pressure applied across the entire area of the opposite side of diaphragm 117. The water is forced to the distributing valve unit 18, whence it is discharged externally of the system in a manner to be described. Water flows from the unit 18 into diaphragm chamber 125 on the vacuum stroke. The corrugated nature of the diaphragm 117 provides an adequate area for full flexure to its maximum extent, and also assists in clearing the diaphragm surface of possible adhering deposits.

Referring to FIGS. 3 and 4, the valving provisions, including the spring urged ball check 107 within the bore 102 of the plunger head extension 94, provide an automatic built-in compensation of oil pressure in the pressure and vacuum cycles of the plungers 77. Thus, when the pump is operated for a long period under conditions of high pressure and heavy load, a tendency of course develops for the oil on the pressure end of cylinder 33 to pass the plunger sealing provisions 95, 96, 97 to the low oil pressure side of the system, represented by the interior of casing 12; and this is apt to cause the high pressure side in cylinder 33, manifold 110 and diaphragm chamber 124 to lack oil in adequate quantity to maintain constant efliciency. Accordingly, the valving arrangements allow a momentary controlled return flow of oil through ball check port 103 to the high side of the plunger head at certain times when the latter is on its vacuum cycle. Thus, the sizes of the head port 103, the plunger extension cap port 104 and the ball 107 are proportioned in relation to the force of spring 108 in such manner that the latter may yield on the suction stroke, permitting oil to pass from the filled transmission casin g 12 into the pressure side of cylinder 33, whenever the oil pressure in casing 12 reaches a predetermined value corresponding to the tension of spring, for example 30 pounds. Thi insures that the part of the system from cylinder 33 up to the diaphragm chamber 124 will be filled at all times with oil. There is no possibly of a build-up of an air pocket in this oil space which, due to the compressibility of the air, would prevent full attainment of the contemplated pumping output pressure.

The distributing unit 18 (reference being had to FIGS. 1, 2 and 2A) comprises an integral, cored out central 'housing member 128, of which the conduits 127 may be integral end extensions, having ports 129 at either lateral end thereof through which each conduit 127 opens to the in terior of the unit 18.

This interior is subdivided into two like halves by an upright wall or partition 1311, providing main entry and discharge manifold chambers 131 on opposite sides thereof for the reversing flow of water in vacuum and pressure cycles of plunger heads 77. Valve plates 132 and 133 are, respectively, disposed across the front and rear side of the central housing member 128, wit-h sealing gaskets interposed, which plates are of an identical nature illustrated in FIG. 2A of the drawings, and the plates 132, 133 are, respectively, parts of water intake and water discharge housing structure at the front and rear sides of unit 18.

As shown in FIGS. 2 and 2A, the plates are generally rectangular in outline and each has a pair of laterally spaced valve ports 135 formed therein. Each such port is adapted to be closed by a flapper valve 136 suitably pivoted at 137 on one side thereof. A recessed intake valve housing member 138 clamps the intake valve plate 132 against the forward side of the central housing part 128; and the above mentioned intake fitting is formed as a part of valve housing 138, being connected by an appropriate conduit 139 with a source of water or other liquid to be pumped.

In similar fashion, a recessed discharge housing member 141 clamps the rear discharge valve plate 133 against the central housing portion 128; and discharge housing 141 is adapted to be connected at its own discharge fitting 22, as by an appropriate conduit 142, with a liquid disposal point. In addition, the rear discharge housing 141 is provided with a small tube 143, for a pressure balancing purpose to be described in connection with FIG. 6.

Referring again to FIG. 2, it seen that the fiapper valve elements 136 of the forward, intake valve plate 132 are disposed to seat over the ports of the latter from its rear; and the elements 136 of the rear, discharge valve plate 133 similarly coact with the latter from its rear.

Accordingly, upon successive suction strokes of the two pumping diaphragms 117, water or other liquid to be pumped is first drawn through the ports of plate 132 into the central manifold chambers 131 at each side of the partition 130, then, on the reverse, pressure throws of the diaphragms 117, discharged through the ports 135 of the other valve plate 133, and through the fitting 22 and discharge conduit or line 142.

The valve housing members 138 and 141 are cored to provide integral bafile elements 143 in alignment with their respective intake and discharge fittings 20 and 22, to avoid or minimize liquid turbulence which might interfere with proper valve action. They also reinforce the housing members 138, 141 to withstand high liquid pressure.

Now referring to FIG. 6, showing the oil pressure balancing and compensating unit 24, the latter is related in function to the valve provisions built into the plunger heads 77, but serves as an agency to protect against unbalanced high oil pressures on the high side of the system. Unit 24 is operatively connected to the respective opposite oil cylinders 33 of each of the cylinder and manifold housings 14 by a fitting 145 threadedly applied to the oil passage 114 of that housing, with flexible oil conduits 146 connecting from these points to a cast tubular housing body 147 of the unit 24. Thus the latter may be mounted at any desired position relative to the remaining symmetric units of pump 10.

Body 147 is cored and reamed to provide a lower control piston or plunger bore 148, in which a cylindrical steel liner sleeve 149 is fitted, and bore 148 opens downwardly into the upper oil chamber 150 of an upper, domed housing part 151 of a diaphragm housing 152 of pressure balancing unit 24. A flexible diaphragm 153 is marginally clamped between coacting flanges of the upper diaphragm housing half 151 and its lower half 154, which handles water, as by means of a pair of clamp rings 155 similar to the clamp rings 120 for the oil-water diaphragm units 16.

A fitting 157 centrally threaded into the bottom of housing part 154 receives the single balancing tube 143 appearing in FIGS. 1, 2 and 6, this tube opening into the water discharge housing 141 of the distributor valve unit 18.

As shown in FIG. 6, the balance control cylinder or sleeve 149 of housing body 147 slidably receives a piston or plunger 159 equipped with a sealing O-ring; and a tubular plunger stem 160 is fixedly connected to plunger member 159 atop the latter. A small passage 161 opens downwardly through the plunger to oil chamber 150. Stern 160 extends upwardly through an opening in a cross partition 162 of housing 147, in which opening the stem is slidably guided for up and down movement. The upper portion of the balancer housing 147 above partition 162 is formed to provide a valve cylinder 163 having annular internal, upper and lower grooves or channels 164, 165 surrounding the valve stem 160 in vertically spaced relation to one another.

Stem 160 is closed at its top, being provided with two series of circumferentially spaced side ports 167, 168 opening therethrough in a vertical spacing from one another corresponding to the vertical spacing of the circumferential channels 164, 165 from one another. The latter communicate respectively with lateral fittings 169 by which they are connected to the respective oil conduits 146 leading from the passage 114 of pump cylinder housings 14.

A hand knob 170 is threaded into the upper, reduced diameter part of housing 147, engaging downwardly against a pressure plug 171 to adjustably regulate the compression of a coil spring 172 acting between plug 171 and the upper closed end of tubular stern 160. This enables a critical pressure to be set, at Which the compensating, balancing or equalizing unit 24 will come into play.

The function of the unit 24 is to protect the system of pump in the event of an unusually high pressure buildup in the discharge housing side 141 of the distributor valve unit 18. This results in the pressurization from beneath, through the balancing tube 143 connecting units 18 and 24, of the diaphragm 153 of the latter unit.

Thus, in the position of the parts shown in FIG. 10, with the pump cylinders 33 under normal operating pressure, the two high pressure conduits 146 are sealed from one another at the tubular stem 160 of plunger 159, the two circumferential series of ports 167, 168 of the latter being blocked by the valve bore 163 beneath the respective grooves or channels 164, 165 of that bore; and the setting of the hand knob 170 in such as to compress the spring 172 sufficiently to maintain this sealed condition under the normal operating discharge pressure.

However, when the pressure builds up enough, beneath diaphragm 153, above a preset critical pressure value in the upper oil chamber 150 of diaphragm housing 152, determined by adjustment of hub 17d, the result is that the plunger 159 is raised until it contacts upwardly against the partition 162 which defines the upper limit of the cylinder bore 148. This brings the respective series of valve member ports 167, 168 into lateral alignment with the channels 164, 165, freely communicating the two oil conduits 146 with one another through these ports and channels or grooves, and also communicating the small passage 161 in plunger 159 with the conduits The result is that pressures are equalized in the two high sides of the system, whereupon spring 172 returns plunger stem 16%) to the seal-01f position of FIG. 10. Hand knob 17% can be manipulated as desired to select any maximum bypass pressure, at which the two cylinders are pressure-equalized to limit discharge pressure in distributor valve unit 18. Insofar as plunger 159 and its stem 160 are concerned, side pressures thereon are equalized.

Thus, should the main discharge line at the fitting 22 of discharge housing 14-1 be shut off while the pump is operating, as by intended operation of a manual nozzle or like valve (not shown), or accidentally closed, the equalizing unit 24 places the main plunger cylinders 33 into communication with one another, so as to eliminate the danger of a motor burn-out or a breakage of some vital part of the pump 10', proper. The pump merely idles at a low rate of current consumption; and the necessity of shutting off the pumps motor between operating cycles, as cycles of automobile washing or the like, is eliminated. Unit 24- also operates as a pulsation dampener, since its diaphragm 153, in moving against the bias of spring 172 under discharge pulse peaks, and then returning, tends to even out the discharge flow.

For the rest, each pump cylinder space 33, hence manifold passage 110 to diaphragm unit 16 and balance conduit 146 to balancing unit 24, is adapted to be filled with oil, independently of the oil level in the cam and differential casing 12, through an upper passage 172 normally closed by a plug 173. The casing 12 is in turn adapted to be independently filled and replenished with oil at a top filler opening norm-ally closed by a plug 174 (FIGS. 1 and 2), and to be drained at an opening at its bottom normally closed by a plug 175. Likewise, water may be drained from each of the diaphragm housings of the pump units 16 through an opening adjacent the bottom thereof closed by a plug 176 (FIG. 6), while oil may be drained from the opposite side of the diaphragm through openings 177.

As in the case of the diaphragm pump unit 16, and the main pump plunger heads 77, unit 24 is, above its diaphragm 153, free of corrosive, adhesive or other eflect tending to hinder free movement of working parts, all of which are sealed in oil, and, accordingly, all are well lubricated. As above indicated, any possible tendency to leak oil pressure past the sealing ring provisions of the head 77 is automatically compensated by flow of oil past the internal sealing provisions of the head upon its suction stroke, should: the pressure in main casing 12 increase predeterminedly.

The cam and cam follower structure 74 and of pump 16' (FIGS. 3 and 4) as united in a unitary, doubleheaded plunger device 76, permits a substantially friction free operation of the pressure plungers, without wasteful side thrust, and also eliminates the need for rod packing and guide provisions usually required in double acting plunger and cylinder units.

In general, the pump 10 is simple compact and sturdy in its parts, providing a dual combination of reciprocating plunger and pumping diaphragm units having fully as great pumping capacity and efficiency as, or greater than, any previous type of plunger pump, or diaphragm pump, or combination of plunger and diaphragm features, of which we are aware.

What we claim as our invention is:

1. A plungendiaphragm type pump structure, comprising a pair of reciprocatory plunger units each including a plunger head operating in a cylinder space to discharge a pressure fluid from an end of said space, a drive unit including a lobe cam common to said plunger units to operate the plunger heads in synchronism, said drive unit comprising a follower device pivotally mounted on each of said heads in radial relation to said cam, each follower device comprising a cradle pivoted on a plunger head, each cradle having means journaling a pair of follower rolls thereon in laterally spaced relation to one another for simultaneous rolling engagement with a lobe surface of said cam, and a diaphragm unit having diaphragm means in communication with said cylinder spaces to be operated by said pressure fluid, said diaphragm unit in turn pressurizing a fluid to be pumped. r

2. A plunger-diaphragm type pump structure, comprising a pair of reciprocatory plunger units each including a plunger head operating in a cylinder space to discharge a pressure fluid from an end of said space, a drive unit including a lobe cam common to said plunger units to operate the plunger heads in synchronism, said plunger heads having a yoke rigidly coupling the same together for reciprocatory movement as a unit, said drive comprising a pair of follower devices mounted on said coupling yoke in radial relation to said cam, each follower device comprising a cradle pivoted on said yoke, each cradle having means journaling a pair of follower ro'lls thereon in laterally spaced relation to one another for simultaneous rolling engagement with a lobe surface of said cam, and a diaphragm unit having diaphragm means in communication with said cylinder spaces to be operated by said pressure fluid, said diaphragm unit in turn press-urizing a fluid to be pumped.

3. The pump structure of claim 1, in which said diaphragm unit comprises a pair of housings each communicating with one of said cylinder spaces and having a flexible diaphragm pressurized by said pressure fluid.

4. The pump structure of claim 2, in which said diaphragm unit comprises a pair of housings each communicating with one of said cylinder spaces and having a flexible diaphragm pressurized by said pressure fluid.

5. A pump comprising a pair of reciprocatory plunger units each including a plunger head operating in a cylinder space, and a drive unit including a lobe cam common to said plunger units to operate the plunger heads in synchronism, said drive unit comprising a follower device pivotally mounted on each of said heads on opposite sides of said cam, each follower device comprising a cradle pivoted on a plunger head, each cradle having means journalling a pair of follower rolls thereon in laterally spaced relation to one another for simultaneous rolling engagement with a lobe surface of said cam, and an oil casing in which said cam is journaled to rotate in oil, said cylinder spaces communicating inwardly of said plunger heads with said casing beneath the level of oil therein, said plunger heads each having a valved passage therethrough, through which passage each cylinder space is adapted to be communicated with the interior of said casing on a non-pumping stroke of the plunger head.

6. A pump comprising a pair of reciprocatory plunger units each including a plunger head operating in a cylinder space, and a drive unit including a lobe cam common to said plunger units to operate the plunger heads in synchronism, said plunger heads having a yoke rigidly coupling the same together for reciprocatory movement as a unit, said drive unit comprising a pair of follower devices mounted on said coupling yoke on opposite sides of said cam, each follower device comprising a cradle pivoted on said yoke, each cradle having means journaling a pair of follower rolls thereon in laterally spaced relation to one another for simultaneous rolling engagement with a lobe surface of said cam, and an oil casing in which said cam is journaled to rotate in oil on an axis passing transversely through said yoke, said cylinder spaces communicating inwardly of said plunger heads with said casing beneath the level of oil therein, said plunger heads each having a valved passage therethrough, through which passage each cylinder space is adapted to be communicated with the interior of said casing on a non-pumping stroke of the plunger head.

7. In a pump of the combined plunger and diaphragm type characterized by a pair of reciprocatory plunger units each including a plunger head operating in a cylinder space, and a flexible pumping member in communication with one of said respective spaces and subject to alternate pressurization and pumping movement on a pumping stroke of one of said plungers, and a drive unit including a lobe cam common to said plunger units to operate the plunger heads in synchronism; the improvement comprising an oil casing in which said cam and cam follower devices are journaled to rotate in oil, said cylinder spaces communicating inwardly of said plunger heads with said casing beneath the level of oil therein, said plunger heads each having a valved passage therethrough through which said cylinder spaces and flexible pumping members are adapted to be communicated with the interior of said casing and beneath the oil level therein on non-pumping strokes of the respective plunger heads.

8. In a pump of the combined plunger and diaphragm type characterized by a pair of reciprocatory plunger units each including a plunger head operating in a cylinder space, and a flexible pumping member in communication with one of said respective spaces and subject to alternate pressurization and pumping movement on a pumping stroke of one of said plungers, and a drive unit including a lobe cam common to said plunger units to operate the plunger heads in synchronism; the improvement comprising a follower device pivotally mounted on each of said heads on opposite sides of said cam, each follower device comprising a cradle pivoted on a plunger head, each cradle having means journaling a pair of follower rolls thereon in laterally spaced relation to one another for simultaneous rolling engagement with a lobe surface of said cam, an oil casing in which said cam and cam follower devices are journaled to rotate in oil, said cylinder spaces communicating inwardly of said plunger heads with said casing beneath the level of oil therein, said plunger heads each having a valved passage therethrough through which said cylinder spaces and flexible pumping members are adapted to be communicated with the interior of said casing and beneath the oil level therein on non-pumping strokes of the respective plunger heads.

9. In a pump of the combined plunger and diaphragm type characterized by a pair of reciprocatory plunger units each including a plunger head operating in a cylinder space, and a flexible pumping member in communication with one of said respective spaces and subject to alternate pressurization and pumping movement on a pumping stroke of one of said plungers, and a drive unit including a lobe cam common to said plunger units to operate the plunger heads in synchronism, said plunger heads having means rigidly coupling the same together for reciprocatory movement as a unit; the improvement comprising a follower device on each of the opposite sides of said cam, each follower device comprising a cradle pivoted on said coupling means, each cradle having means journaling a pair of follower rolls thereon in laterally spaced relation to one another for simultaneous rolling engagement with a lobe surface of said cam, an oil casing in which said cam and cam follower devices are journaled to rotate in oil, said cylinder spaces communicating inwardly of said plunger heads with said casing beneath the level of oil therein, said plunger heads each having a valved passage therethrough through which said cylinder spaces and flexible pumping members are adapted to be communicated with the interior of said casing and beneath the oil level therein on non-pumping strokes of the respective plunger heads.

10. A pump structure comprising a pair of diaphragm units each including head members and a flexible diaphragm clamped therebetween to provide first and second pumping chambers in each diaphragm unit sealed from one another by said diaphragm, said unit having means to connect the first chamber thereof with a source of pressure liquid and means to connect the second chamber thereof with a liquid pumped by the pump, with the diaphragm thereof pressurized over the entire area of both sides thereof by the pressure liquid and the pumped liquid, said diaphragm unit having a ring clamping the diaphragm thereof to the head member thereof on its pressure liquid side, and means to clamp the last named head member and said clamp ring against the other head member of the diaphragm unit, a pump unit constituting said source of pressure liquid and supplying the liquid to the first chamber of each of said diaphragm units, and balancing valve means to connect the respective first chambers of said diaphragm units with the output of said pump unit in response to variations in pressure in said first chambers.

11. A pump structure comprising a pair of diaphragm units each including head members and a flexible diaphragm clamped therebetween to provide first and second pumping chambers in each diaphragm unit sealed from one another by said diaphragm, each of said units having means to connect the first chamber thereof with a source of pressure liquid and means to connect the second chamber thereof with a liquid pumped by the pump, with the diaphragm thereof pressurized over the entire area of both sides thereof by the pressure liquid and the pump liquid, said diaphragm units each having a ring clamping the diaphragm thereof to the head member thereof on its pressure liquid side, and split ring means to wedgingly clamp the last named head member and said clamp ring against the other head member of the diaphragm unit, a pump unit constituting said source of pressure liquid and supplying the liquid to the first chamber of each of said diaphragm units, and balancing valve means to connect the respective first chambers of said diaphragm units with the output of said pump unit in response to variations in pressure in said first chambers.

12. A pump comprising a pair of diaphragm units each including head members and a flexible diaphragm clamped therebetween to provide first and second pumping chambers in each diaphragm unit sealed from one another by said diaphragm, each of said units having means to connect the first chamber thereof with a source of pressure liquid and means to connect the second chamber thereof with a liquid pumped by the pump, with the diaphragm thereof pressurized over the entire area thereof by the pressure liquid pressure, and a balancing unit to equalize the pressure in said first diaphragm chambers under-a pressure of the liquid pumped, said balancing unit comprising a valve device having connections adapted to be opened to inter-communicate the pressures of the respective first pumping chambers, and means subject to the pressure of the liquid pumped and operable upon said valve device in response to said excessive pressure to open said connections.

13. A pump comprising a pair of diaphragm units each including head members and a flexible diaphragm clamped therebetweenito provide first and second pumping chambersin each diaphragm unit sealed from one another by said diaphragm, each of said units having means to connect the first chamber thereof with a source of pressure liquid and means to connectthe second chamber thereof with a liquid pumped by the pump, with the diaphragm thereof pressurized over the entire area thereof by the pressure liquid pressure, said diaphragm units each having a ring clamping the diaphragm thereof to the head member thereof on its pressure liquid side, and means to clamp the last named head member and said clamp ring against the other head member of the diaphragm unit, and a balancing unit to equalize the pressure in said first diaphragm chambers under a pressure of the liquid pumped, said balancing unit comprising a valve device having connections adapted to be opened to inter-communicate the pressures of the respective first pumping chambers, and means subject to the pressure of the liquid pumped and operable upon said valve device in response to said excessive pressure to open said connections.

14. A pump comprising a pair of opposed, axially aligned cylinders, a plunger reciprocable in each cylinder to pump a pressure liquid therefrom, a pair of secondary pumping units each including a flexible pressure responsive member separating the unit into first and second pumping chambers sealed from one another by said member, conduit means connecting said first chambers with the res ective cylinders for pressurization of said flexible member by said pressure liquid on pumping strokes of said plungers, a distributor valve unit common to said secondary pumping units having conduit means connecting the same to said units at the respective second chambers of the latter, said distributor unit having a pair of reverse liquid flow chambers communicating with said last named conduit means, liquid intake and discharge housings, and automatic valve means separating said reverse flow chambers from the respective intake and discharge housings for the intake and discharge flow of a pumped liquid through said reverse flow chambers and last named conduit means upon reversing action of said plungers,- thus to alternately pressurize and depressurize said flexible pressure responsive members, and a balancing unit to equalize the pressure in said respective cylinders and first chambers under an excessive pressure in the discharge housing of said distributor unit, said balancing unit comprising a valve device having connections adapted to be opened to inter-communicate the pressures of the respective cylinders and first chambers, and means subject to pressure in said discharge housing and operable upon said valve device in response to said excessive pressure in the discharge housing to open said connections.

15. A pump comprising a pair of opposed, axially aligned cylinders, a plunger reciprocable in each cylinder to pump a pressure liquid therefrom, a pair of diaphragm units each including head members and a flexible diaphragm clamped between said members to provide first and second pumping chambers in each diaphragm unit sealed from one another by said diaphragm, conduit means connecting said first chambers with the respective cylinders for pressurization of the respective diaphragms over the entire area thereof by said pressure liquid on pumping strokes of said plungers, .a distributor valve unit common to said diaphragm units having conduit means connecting the same to said units at the respective second chambers of the latter, said distributor unit having a pair of reverse liquid flow chambers communicating with said last named conduit means, liquid intake and discharge housings, and automatic valve means separating said reverse flow chambers from the respective intake and discharge housings for the intake and discharge flow of a pumped liquid through said reverse flow chambers and last named conduit means upon reversing action of said plungers, thus to alternately pressurize and depressurize said diaphragms, and a balancing unit to equalize the pressure in said respective cylinders and first chambers under an excessive pressure in the discharge housing of said distributor unit, said balancing unit comprising a valve device having connections adapted to be opened to intercommunicate the pressures of the respective cylinders and first chambers, and means subject to pressure in said discharge housing and operable upon said valve device in response to said excessive pressure in the discharge housing to open said connections.

16. A pump comprising a pair of opposed, axially aligned cylinders, a plunger reciprocable in each cylinder, said plungers being rigidly coupled for reciprocation in unison to pump a pressure liquid from said respective cylinders, a pair of diaphragm units each including head members and a flexible diaphragm clamped therebetween to provide first and second pumping chambers in each diaphragm unit sealed from one another by said diaphragm, conduit means connecting said first chambers with the respective cylinders for pressurization of the respective diaphragms over the entire area thereof by said pressure liquid on pumping strokes of said plungers, a distributor valve unit common to said diaphragm units having conduit means connecting the same to said units at the respective second chambers of the latter, said distributor unit having a pair of reverse liquid flow chambers communicating with said last named conduit means, liquid intake and discharge housings, and automatic valve means separating said reverse flow chambers from the respective intake and discharge housings for the intake and discharge flow of a pumped liquid through said reverse flow chambers and last named conduit means upon reversing action of said plungers, thus to alternately pressurize and depressurize said diaphragms, and a balancing unit to equalize the pressure in said respective cylinders and first diaphragm pumping chambers under an excessive pressure in the discharge housing of said distributor unit, said balancing unit comprising a valve device having connections adapted to be opened to inter-communicate the pressures of the respective cylinders and first pumping chambers, and means subject to pressure in said discharge housing and operable upon said valve device in response to said excessive pressure in the discharge housing to open said connections.

17. A pump comprising a pair of reciprocatory plunger units each including a plunger head operating radially in a cylinder space, and a drive unit radially inwardly of said plunger units, said drive unit including a rotary cam common to said plunger units to operate the plunger heads in synchronism to discharge fluid radially outward of said cylinder spaces, said drive unit comprising a follower device pivotally mounted on each of said heads, each follower device comprising a cradle pivoted on a plunger head, each cradle having means journaling a pair of follower rolls thereon in laterally spaced relation to one another for simultaneous rolling engagement with a surface of said cam.

18. The pump of claim 17, in which said plunger heads have a yoke rigidly coupling the same together for reciprocatory movement as a unit.

19. A pump structure comprising a diaphragm unit including head members and a flexible diaphragm clamped therebetween to provide first and second pumping cham- 'bers in each diaphragm unit sealed from one another by said diaphragm, said unit having means to connect the first chamber thereof with a source of pressure liquid and means to connect the second chamber thereof with a liquid pumped by the pump, with the diaphragm thereof under pressure over the entire area of both sides thereof by the pressure liquid and the pumped liquid, a pump unit constituting said source of pressure liquid and supplying the liquid to the first chamber of each of said diaphragm units, and balancing valve means to connect the respective first chambers of said diaphragm units with the output of said pump unit in response to variations in pressure in said first chambers.

20. A pump comprising a pair of diaphragm units each including head members and a flexible diaphragm clamped therebetween to provide first and second chambers in each diaphragm unit sealed from one another by said diaphragm, each of said units having the diaphragm thereof operated on the side of the first chamber thereof from a source of pressure liquid, and means to connect the second chamber thereof with a liquid pumped by the pump, and a balancing unit to equalize the pressure in said first diaphragm chambers under a pressure of the liquid pumped, said balancing unit comprising a valve de- 15 vice having connections adapted to be opened to intercommunicate the pressures of the respective first pumping chambers, and means subject to the pressure of the liquid pumped and operable upon said valve device in response to said excessive pressure to open said connections.

References Cited by the Examiner UNITED STATES PATENTS 1,301,485 4/1919 Mueller 10344 1,850,083 3/1932 Noltein 10'3171 X 2,217,796 10/1940 Dell 103-161 2,362,822 11/1944 Houser et al. 103-44 X 2,695,131 11/1954 Price. 3,034,450 5/1962 Kruckeberg 103l50 FOREIGN PATENTS 251,213 10/1948 Switzerland,

ROBERT M. WALKER, Primary Examiner. 

1. A PLUNGER-DIAPHRAGM TYPE PUMP STRUCTURE, COMPRISING A PAIR OF RECIPROCATORY PLUNGER UNITS EACH INCLUDING A PLUNGER HEAD OPERATING IN A CYLINDER SPACE TO DISCHARGE A PRESSURE FLUID FROM AN END OF SAID SPACE, A DRIVE UNIT INCLUDING A LOBE CAM COMMON TO SAID PLUNGER UNITS TO OPERATE THE PLUNGER HEADS IN SYNCHRONISM, SAID DRIVE UNIT COMPRISING A FOLLOWER DEVICE PIVOTALLY MOUNTED ON EACH OF SAID HEADS IN RADIAL RELATION TO SAID CAM, EACH FOLLOWER DEVICE COMPRISING A CRADLE PIVOTED ON A PLUNGER HEAD, EACH CRADLE HAVING MEANS JOURNALING A PAIR OF FOLLOWER ROLLS THEREON IN LATERALLY SPACED RELATION TO ONE ANOTHER FOR SIMULTANEOUS ROLLING ENGAGEMENT WITH A LOBE SURFACE OF SAID CAM, AND A DIAPHRAGM UNIT HAVING DIAPHRAGM MEANS IN COMMUNICATION WITH SAID CYLINDER SPACES TO BE OPERATED BY SAID PRESSURE FLUID, SAID DIAPHRAGM UNIT IN TURN PRESSURIZING A FLUID TO BE PUMPED. 